WO2022085317A1

WO2022085317A1 - Choke coil

Info

Publication number: WO2022085317A1
Application number: PCT/JP2021/032796
Authority: WO
Inventors: 雅文井上; 康臣 ▲高▼橋; 恒次今西
Original assignee: 株式会社エス・エッチ・ティ
Priority date: 2020-10-19
Filing date: 2021-09-07
Publication date: 2022-04-28
Also published as: CN116391241A; US20230411062A1; DE112021005505T5; JP2022066635A; TW202232523A; KR20230091898A

Abstract

The present invention provides a choke coil that has a high space factor and manufacturing efficiency and is suitable for high frequency circuits.　The present invention relates to a choke coil 10 comprising a pair of core pieces 20, 20 comprising: arc-shaped divided cores 31 with end faces 32, 32a opposing each other to form a toroidal shape; insulating coating materials 34 coating the divided cores for electric insulation and having flanges 35, 35 protruding outward from the respective end faces of the divided cores; coating wires 40 wound around the outer periphery of the insulating coating materials; and terminals 50, 50 to which the coating wires are electrically connected and which are each provided near the flanges. The pair of core pieces 20, 20 are disposed with the end faces of the divide core opposing each other. The coating wires comprise a plurality of wires wound in parallel around the outer periphery of the insulating coating materials without twisting. The coating wires are electrically connected to the terminals.

Description

choke coil

The present invention relates to a choke coil used in a high-frequency current suppression circuit, a waveform shaping circuit, a power factor improvement circuit, various switching power supply circuits, etc. in a device that handles alternating current such as a switching power supply device and an inverter device, and more specifically. Is a choke coil with a toroidal form used in a switching power supply circuit driven by a high frequency with a frequency f of about 10 kHz to 150 kHz, but has a high space factor. It relates to a choke coil which has high manufacturing efficiency and realizes high quality and stable supply.

The choke coil used in the power supply circuit and high frequency circuit of various AC devices is configured by winding a coated wire (magnet wire) multiple times around a toroidal core covered with an insulating coating material formed by bobbins or surface treatment.

In order to wind the covered wire around the toroidal core, the winding process of pulling out the covered wire through the central window must be repeated for the number of design turns according to the required characteristics. In order to reduce the size of the choke coil, the central window of the toroidal core is required to be designed to the minimum, and this winding work is difficult to mechanize and has to rely on manual work. However, the number of turns of the covered wire needs to be performed several hundred times or more when the wire diameter is relatively thin, for example, when the diameter is 0.8 mm or less, and when the wire diameter is thick, for example, 2.0 mm or more, the number of turns needs to be increased. Although the number of turns is small, the covered wire is hard, so workability is poor and a heavy burden is placed on the operator, and there is a problem that it is difficult to continue mass production.

Therefore, in order to solve the above-mentioned winding problem, a choke coil has been proposed in which an arc-shaped divided core is insulated and coated, a core piece wound with a covered wire is prepared, and the core piece is recombined to form a toroidal shape (for example). , Patent Documents 1 and 2). The covered wire starts at one end edge of the split core, is wound around the body of the split core, and then is wound so as to end at the other end edge.

Microfilm of Jitsugyo Hei 01-98725 (Jitsukaihei 03-38603) Japanese Unexamined Patent Publication No. 2001-52245

In recent years, the speed of power semiconductor elements used in switching power supply devices and inverter devices has been remarkably increased, and the choke coils used in these power supply circuits are also required to suppress high frequency loss and reduce the size suitable for high frequency circuits. The loss of the choke coil is composed of iron loss and copper loss, and the iron loss depends on the magnetic material used for the core.

On the other hand, one of the causes of copper loss is the DC resistance loss of the winding. In order to reduce the DC resistance loss of the winding, it is required to increase the ratio of the copper wire portion of the covered wire to the core, the so-called space factor. In the case of

Patent Documents

1 and 2, in order to reduce the DC resistance loss, it is effective to increase the space factor and use a covered wire having a larger diameter while ensuring the number of turns on the split core, but the diameter is larger. It is difficult to wind the covered wire around the arc-shaped split core many times, not only by machine but also by manual winding, and it is not realistic because the covered wire is misaligned and the wound covered wire is broken.

Further, as the second cause of copper loss, there is a skin effect phenomenon due to a high frequency current, and as the frequency f increases, the internal resistance of the copper wire increases and the current tends to be on the surface. In the case of copper wire, the skin depth is expressed as 66.1 / f ^1/2 (mm), and it is known that the loss increases and heat is generated by reducing the cross-sectional area of the effective copper wire. It is necessary to select the copper wire diameter in the coil suitable for the frequency f and prepare a number having a cross-sectional area according to the current capacity.

Therefore, it is conceivable to wind a litz wire (reference numeral 91 in FIGS. 13 to 15) in which a plurality of copper wires 92 having a cross-sectional area corresponding to the current capacity are twisted and bundled so as not to be scattered around the split core 31. .. However, as shown in Examples described later, the litz wire 91 has a large gap s between the copper wires 92, a bulky coating, and a gap S between the twisted and thickened wires, so that the space factor deteriorates. .. As a result, the number of turns of the central window of the toroidal core is significantly reduced, which leads to an increase in the size of the core. Further, since the litz wire 91 is easily unwound due to its residual stress (restoring force) during and after winding, there is a problem that the finished product swells and becomes large. Furthermore, since the litz wire must be specially designed and prepared according to the wire diameter and the number of twists according to the frequency, there is a problem that labor and cost increase are unavoidable.

An object of the present invention is to provide a choke coil suitable for a high frequency circuit having a high space factor and high manufacturing efficiency.

The choke coil according to the present invention is
An arc-shaped split core that becomes a toroidal shape by facing the end faces,
An insulating coating material having an electrically insulating coating on the split core and having a flange protruding outward from each end face of the split core.
The coated wire wound around the outer circumference of the insulating coating material and
A terminal to which the covered wire is electrically connected and provided in the vicinity of the collar, respectively.
A pair of core pieces
A choke coil arranged so that the end faces of the split core face each other.
A plurality of the coated wires are wound in parallel on the outer circumference of the insulating coating material without being twisted, and each coated wire is electrically connected to the terminal.

The coated wire is wound in a layered manner along the peripheral surface of the insulating coating material, and the inner peripheral surface side of the insulating coating material is composed of one coated wire on the side close to the inner peripheral surface. It is possible to form a structure in which one layer and a second layer composed of one covered wire are sequentially laminated on the outer periphery thereof.

The covered wire can be folded back and wound at the terminal.

A plurality of coated wires can be wound around the insulating coating material without folding back.

It is desirable that the coated wire is wound around the inner peripheral surface side of the insulating coating material side so that the center bulges.

The terminal can be electrically connected to the covered wire by resistance welding, welding method, or soldering.

Further, the choke coil product of the present invention is configured by coating the outer periphery of the choke coil described above with a resin.

According to the choke coil of the present invention, since a plurality of covered wires are wound in parallel in each core piece, high density winding can be achieved as compared with litz wire, and a high space factor can be secured. As a result, it is possible to achieve miniaturization and high performance of the choke coil. Since the covered wire may be wound around an arc-shaped split core coated with insulation, it can be manufactured by making full use of an automatic winding device using a machine, and the manufacturing efficiency can be improved. In particular, in a configuration in which a plurality of coated wires are wound in a layered manner, a first layer composed of one coated wire is sequentially laminated on the inner peripheral surface side of the core piece, and a second layer composed of one coated wire is sequentially laminated on the outer peripheral side thereof. This has the advantage that the covered wire can be wound stably without any misalignment, collapse, or variation of the covered wire.

Further, since a toroidal choke coil can be obtained by abutting the end faces of the pair of core pieces, the manufacturing efficiency of the choke coil can be improved as much as possible.

As mentioned above, the covered wire may be a plurality of copper wires made of a single wire wound in parallel, and it is not necessary to use an expensive litz wire that requires a special design. Therefore, there is an advantage that the cost can be reduced as compared with the litz wire, the space factor is high because it is not twisted, and the number of wires can be set arbitrarily.

The choke coil of the present invention is suitable as a choke coil used in a high-frequency current suppression circuit, a waveform shaping circuit, a power factor improvement circuit, various switching power supply circuits, etc. in a device that handles alternating current such as a switching power supply device and an inverter device. In addition, since the covered wire can be wound stably without any positional deviation, collapse, or variation of the covered wire, it is possible to reduce variations in the frequency characteristics and inductance characteristics of the high-frequency choke coil caused by these. In particular, a choke coil having a toroidal form, which is an efficient ideal magnetic circuit used for a switching power supply circuit driven by a high frequency with a frequency f of about 10 kHz to 150 kHz, is used for a winding machine having a high space factor. By making full use of the automatic winding device used, it is possible to realize high manufacturing efficiency, high quality and stable supply.

FIG. 1 is a perspective view of the choke coil of the present invention. FIG. 2 is a perspective view of a split core coated with a resin other than the end face. FIG. 3 is a perspective view of the core piece (before mounting the terminal) around which the covered wire is wound. FIG. 4 is a plan view of FIG. FIG. 5 is a cross-sectional view of the core piece, and is a diagram showing the processes (a) to (c) of winding the covered wire in a layered manner. FIG. 6 is a cross-sectional view of a core piece around which (a) a covered wire (shown only on the central window side) is wound, and (b) an enlarged view of an enclosed portion A. It is sectional drawing which shows the state which the covered wire was wound until the central window on the inner peripheral side of a core piece was almost closed. FIG. 8 is a perspective view in which a pair of core pieces before mounting the terminals are arranged so that their end faces face each other. FIG. 9 is a perspective view in which a pair of core pieces equipped with terminals are arranged so that their end faces face each other. 10A and 10B are explanatory views (a) to (c) showing a process of sandwiching a covered wire between terminals and fusing. FIG. 11 is a perspective view showing a process of mounting the core piece on the casing. FIG. 12 is a perspective view of a choke coil product in which the choke coil of the present invention is housed in a casing by coating with a resin. 13A and 13B are a cross-sectional view of a core piece wound with a litz wire for comparison, and FIG. 13B is a cross-sectional view of the core piece wound with a litz wire until the central window is almost closed. 14 is an enlarged view of the box B of FIG. 13. FIG. 15 is an explanatory diagram comparing (a) the core piece of the present invention and (b) the space factor of the core piece wound with a litz wire.

Hereinafter, the choke coil 10 according to the embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is an external perspective view of a choke coil 10 according to an embodiment of the present invention. The choke coil 10 is configured by placing

arcuate core pieces

20 and 20 around which a coated wire 40 is wound on a resin base 60, respectively, as shown in detail and a manufacturing process below. The end edges 40a and 40a of the covered wire 40 are electrically connected to the terminals 50, respectively. In the figure, three terminals 50 are shown.

The choke coil 10 having the above configuration can be manufactured as follows.

The core piece 20 is configured by winding a coated wire 40 around the outer periphery of the body of the coated core 30 shown in FIG. 2, as shown in FIGS. 3 and 4, and attaching a terminal 50 as shown in FIG.

As shown in FIG. 2, the coated core 30 is formed by covering the outer periphery of an arcuate split core 31 made of a magnetic material (the cross-sectional shape of the split core 31 is shown in FIG. 5) with a bobbin 34 made of an electrically insulating coating material. It is composed of. More specifically, in the split core 31, the portion other than the end faces 32 and 32a is covered with the bobbin 34. In addition, instead of the bobbin 34, an insulating coating material formed by surface treatment can also be adopted.

The inside of the coated core 30 can be in the form of an arc having a semicircular recess forming the central window 21 of the toroidal core, and the pair of

coated cores

30 and 30 have end faces 32. , 32a are arranged so as to face each other to form a planar view ring. The shapes of the covering cores 30 and 30 (divided cores 31 and 31) may be combined into an elliptical shape in a plan view, a track shape, a rectangular shape, or the like. Further, the cross-sectional shape of the split core 31 is not limited, but is substantially rectangular in the drawing. Examples of the split core 31 include a dust core and a ferrite core obtained by compacting and sintering magnetic powder. As the arc-shaped split core 31, one obtained by cutting a toroidal shape or one previously formed into an arc shape can be adopted. However, since the dust core is affected by the high-pressure forming pressure, it is desirable to cut the toroidal shape instead of forming it into an arc shape in advance. Further, when the ferrite core is fired in an arc shape, the shapes of the end faces 32 and 32a which are the butt surfaces are affected by the firing deformation, so it is desirable to cut the toroidal shape. In any case, the cut split core has better magnetic characteristics, so it is desirable to cut the toroidal shape to create the split core.

The bobbin 34 can be created by forming an insulating resin on the outer periphery of the split core 31 by insert molding or the like, and the bobbin 34 may have a shape in which the

flange portions

35, 35 are projected in the vicinity of the end faces 32, 32a of the split core 31. can.

The coated core 30 can be created, for example, by insert-molding a toroidal core to form a covering of the bobbin 34 and then cutting along the flange portion 35. For cutting, water-cooled grindstone rotary cutting, wire saw, fiber laser cutting using a laser, water laser cutting and the like can be adopted.

A coated wire 40 is wound around the coated core 30 from one end surface 32 to the other end surface 32a to form a core piece 20 as shown in FIGS. 3 and 4. The coated wire 40 can be configured as a single wire, and an insulatingly coated copper wire such as a magnet wire or a fused wire having a fusion function on the surface of the insulating coating can be adopted.

Specifically, as shown in the figure, the covered wire 40 is wound with a plurality of single-line covered wires 40 in parallel around the coated core 30. For example, as shown in FIG. 5A, first, the first covered wire 41 is wound around the covered core 30. The first covered wire 41 is wound along the inner peripheral surface until the inner peripheral surface (center window 21 side) of the coated core 30 is almost filled, and constitutes the first layer 41b of the coated wire 40. It is desirable that the edge of the covered wire 41 projects to the outside of the flange portion 35 as shown by reference numeral 40a in FIGS. 3 and 4 and reference numeral 41a in FIG. 5 (a).

Subsequently, as shown in FIG. 5 (b), the second covered wire 42 is wound around. The second covered wire 42 is wound so that the central window 21 side is overlapped on the first layer 41b to form the second layer 42b (see FIG. 6B: however, the covered wire is the central window. Only the 21 side is shown). It is desirable that the second covered wire 42 fits into the valley portion formed in the covered wire 41 which is in close contact with the first one of the first layer 41b and is wound so as to be in a laminated state such as bale stacking. As a result, the gap s between the covered

wires

41 and 42 can be reduced, and the space factor can be improved. Since the outer peripheral side of the coated core 30 has a gap between the adjacent first covered wires 41, the second covered wire 42 is wound so as to be sequentially fitted between them. Similar to the first line, the end edge of the second covered wire 42 is projected to the outside of the flange portion 35 as shown by reference numeral 40a in FIGS. 3 and 4 and reference numeral 42b in FIG. 5 (b).

Further, as shown in FIG. 5 (c), the third covered wire 43 is wound. The third covered wire 43 is wound around the central window 21 side so as to fit into the valley portion formed in the covered wire 42 in close contact with each other next to the second layer, as in the second layer 42b (see FIG. 6 (b)). ). Further, in the third coated wire 43, if there is a gap between the first and second

covered wires

41 and 42, the outer peripheral side of the coated core 30 is wound so as to be sequentially fitted between them, and there is no gap. In the case, it is wound so as to fit into the valley portion of these covered

wires

41 and 42. The end edge of the third covered wire 43 is also projected to the outside of the flange portion 35 as shown by reference numeral 40a in FIGS. 3 and 4 and reference numeral 43b in FIG. 5 (c).

In the above procedure, the covered wire 40 may be wound in layers for the required performance. FIG. 6 shows a core piece 20 in which a coated wire 40 (41 to 47) is wound around a coated core 30 so as to form seven layers (41b to 47b) (however, the coated wire is shown only on the central window 21 side) and its enclosure. The enlarged view of the part A is shown. In the enlarged view 6 (b), the covered wire 40 is wound around the central window 21 side of the covered core 30 so as to have seven layers as shown by reference numerals 1 to 7. Assuming that the number of windings of the covered wire of 1 is 35 turns each, the winding of 7 × 35 = 245 turns is applied by the 7-layer parallel winding, and a coil suitable for high frequency can be formed.

FIG. 7 shows a state in which the covered wire is wound until the central window 21 of the covered core 30 is almost closed. In the illustrated example, by winding the covered wire 40 so as to overlap 10 layers, the central window 21 side approaches the form slightly bulging toward the center of the arc, that is, it touches the line connecting the end faces 32, 32a. The winding is done like this. As a result, similarly to the above, assuming that the number of windings of one covered wire 40 is 35 turns, winding of 10 × 35 = 350 turns can be performed by 10-layer parallel winding. This makes it possible to form a coil more suitable for high frequencies.

The winding of the coated wire 40 can be performed in the same direction from one end surface 32 of the coated core 30 toward the other end surface 32a, that is, without folding back. Further, one of the covered wires 40 may be wound from one end surface 32 toward the other end surface 32a (outward route), and then folded back from the end surface 32a side toward the end surface 32 (return route). In this case, the covered wire 40 is folded back 180 degrees with respect to the outward route, and the return route is in the opposite direction, that is, the covered wire 40 is wound around the coated core 30 in the same winding direction when viewed from one end surface 32 side. With either method, winding can be performed automatically using an automatic winding device using a nozzle such as a fryer type winding machine, and the covered wire 40 can be wound precisely, and the turn The number (number of turns) can also be controlled accurately. Further, by adopting the automatic winding device, it is possible to realize high manufacturing efficiency, high quality and stable supply.

While winding the coated wire 40, it is desirable that the edge 41a and the like of the coated wire 40 that has already been wound are sandwiched by jigs in order. This makes it possible to prevent variations in the edge 41a and the like and rewinding. In addition, instead of the jig, it may be sequentially sandwiched between the bent portions 51 (see FIG. 9) of the terminal 50.

Then, as shown in FIG. 9, a terminal 50 is attached to the covered wire 40 wound around the core piece 20, and the end edges 40a (41a to 47a) of the covered wire 40 are electrically connected to the terminal 50. To. For example, the terminal 50 may have a shape in which an external contact portion 52 is formed downward and a bent portion 51 sandwiching the covered wire 40 is formed on the upper side as shown in FIG. 10 (a). In this case, first, as shown in FIG. 10 (a), the edge 40a (41a to 47a) of the covered wire 40 (41 to 47) is sandwiched between the bent portions 51, and the electric resistance is as shown in FIG. 10 (b). Insulation of the edge 40a (41a to 47a) of the coated wire 40 (41 to 47) by fusing while bending the bent portion 51 at the

electrode terminals

80 and 81 of the fusing which is the hot caulking welding using the above. The coating is removed and the edge 40a and the terminal 50 can be electrically and structurally connected as shown in FIG. 10 (c). The coated wire 40 and the terminal 50 are not limited to fusing processing, but various welding methods such as resistance welding, TIG welding and plasma welding, or chemicals such as mechanical peeling, strong acid and strong alkaline agent are used. It may be soldered after the film is peeled off. By any of the processing methods, the insulating coating of the coated wire 40 can be removed and the electrical connection to the terminal 50 can be performed.

Therefore, in the core piece 20 in which the terminal 50 and the covered wire 40 are electrically connected, the two are paired, and the end faces 32, 32a of the split core 31 and the end faces 32, 32a of the other split core 31 are paired with each other. The

collars

35 and 35 are butted so as to face each other. Then, as shown in FIG. 11, the choke coil 10 shown in FIG. 1 is obtained by placing it on the base 60. The end faces of the divided

cores

31 and 31 may be butted so as to be in close contact with each other in order to obtain a desired DC superimposition characteristic (inductance vs. current), or an electrically insulating spacer may be inserted to form a gap. You may.

In the obtained choke coil 10, the covered wire 40 can be wound tightly around each core piece 20, and the space factor of the covered wire 40 is increased to 60% to 70% or more as shown in FIG. 15 described later. Can be done. By improving the space factor of the choke coil 10, the inductance can be increased, and the choke coil 10 itself can be made smaller, lighter, more efficient, and has smaller DC resistance. In particular, since the covered wire 40 can be a single wire having various diameters for general purposes or a single wire such as a magnet wire, it is not necessary to use an expensive and time-consuming litz wire that requires a special design. Therefore, the cost can be reduced and the manufacturing lead time can be shortened as compared with the litz wire, the space factor is high because the wire is not twisted, and the number of wires can be set arbitrarily.

Since the

flange portions

35, 35 are formed on the core piece 20, electrical insulation is achieved between the covered

wires

40, 40 of the

core pieces

20, 20 to prevent electrical contact and short circuit between them. can. It is desirable to achieve electrical insulation between the covered

wires

40 and 40 by inserting an electrically insulating resin plate or the like also on the central window 21 side of the

core pieces

20 and 20.

The choke coil 10 has only a configuration in which the

core pieces

20 and 20 are placed on the base 60, and since the

core pieces

20 and 20 are not fixed to each other, a gap may occur in the butt portion and the choke coil 10 may open. The

core pieces

20 and 20 are generally fixed to each other with an adhesive, but as shown in FIG. 12, the choke coil 10 is resin-coated by insert molding, resin casting (potting), or the like, and the casing 70 is used. It can be made into a choke coil product 11. By accommodating the choke coil 10 in the casing 70, the heat dissipation characteristics can be enhanced and the heat can be equalized. A high thermal conductive resin can be used for the casing 70, or a structure having a heat sink can be used. Further, as shown in FIG. 12, the heat dissipation property can be further improved by flattening the top surface of the casing 70 and increasing the contact area by utilizing a heat sink or a chassis to facilitate heat dissipation. Since the top surface of the casing 70 is flattened, the heat dissipation function including the set mounting can be improved by the insulating function and the heat dissipation function of the casing 70 without using an insulating silicone sheet having high thermal conductivity.

The choke coil product 11 having the above configuration is installed on a board or the like and can be used as a choke coil for noise prevention circuits, waveform shaping circuits, resonance circuits, various switching circuits, etc. in AC devices such as power supply circuits and inverters. The choke coil product 11 of the present invention is suitable as a choke coil used as a countermeasure against high frequency distortion current in a circuit provided with a power factor improving circuit (Power Factor Correction) in a switching power supply or the like used as a choke coil product for high frequencies exceeding 10 kHz. It can also be used as a high-frequency smoothing choke coil for impedance matching. However, even for high frequency applications, it is not suitable for filter applications such as common mode choke coils and normal mode choke coils that obtain attenuation at high frequencies.

The above description is for explaining the present invention, and should not be understood to limit or limit the scope of the invention described in the claims. In addition, the configuration of each part of the present invention is not limited to the above embodiment, and it goes without saying that various modifications can be made within the technical scope described in the claims.

The core piece 20 formed by winding the covered wire 40 of the present invention in parallel and the core piece 90 formed by winding the litz wire 91 were prepared, and their space factors were compared. An example of the invention is 7 layers shown in FIG. 6 × 35 turns each for 245 turns. In the comparative example, the 7-strand litz wire 91 is wound around the outer circumference of the coated core as shown in FIG. 13 (a), and as shown in FIG. 13 (b), the number of turns is 35 as in the invention example. It is wound around and has a total of 245 turns. A cross-sectional view of the wound portion of the covered wire 40 of the invention example is shown in FIG. 6 (b), and a cross-sectional view of the enclosed portion B of FIG. 13 (b) is shown in FIG. 14 for the core piece 90 of the comparative example. Further, with respect to FIGS. 6 (b) and 14, the clearance portions that do not contribute to the space factor are shown in black in FIGS. 15 (a) and 15 (b), respectively.

With reference to FIGS. 6 (a) and 13 (b), the invention example can be wound thinner without swelling toward the central window 21 side as compared with the comparative example, even if the number of turns is the same. As can be seen by comparing FIG. 6 (b) and FIG. 14, in the invention example, the coated wires 40 are in close contact with each other and can be wound in a layer without clearance, whereas in the comparative example, the litz wire is used. There is a gap between the 91s, and further between the copper wires 92 constituting the litz wire 91. More specifically, as shown in black in FIGS. 15 (a) and 15 (b), in the invention example, the gap s between the covered wires 40 (40 to 47) is relatively small, but the comparative example. It can be seen that in addition to the gap s between the copper wires 92, the wound is wound with the gap S between the litz wires 91 existing. As a result, the space factor of the invention example was about 65%, whereas the space factor of the comparative example was about 45%, which was about 20% or more low. By improving the space factor by 20% with the same core size, it is possible to increase the inductance value by the square of 1.2 (1.44) times. In other words, in order to have the same performance, the invention example can reduce the core size by about 20% as compared with the comparative example.

In the invention example, since the single-wire covered wire 40 can be adopted, the degree of freedom in wire diameter, material, etc. is higher than that of the litz wire 91. In the example of the invention, copper loss (DC resistance) and heat generation can be reduced by about 17% by simply thickening the space factor by 10% (for example, thickening 0.5 mm in diameter to 0.55 mm in diameter).

10 Choke coil 11 Choke coil product 20 Core piece 21 Central window 30 Covered core 31 Divided core 32 End face 32a End face 34 Bobbin 35 Collar 40 (41 to 47) Covered wire 40a (41a to 47a) Edge 50 terminal

Claims

An arc-shaped split core that becomes a toroidal shape by facing the end faces,
An insulating coating material having an electrically insulating coating on the split core and having a flange protruding outward from each end face of the split core.
The coated wire wound around the outer circumference of the insulating coating material and
A terminal to which the covered wire is electrically connected and provided in the vicinity of the collar, respectively.
A pair of core pieces
A choke coil arranged so that the end faces of the split core face each other.
A plurality of the coated wires are wound in parallel on the outer circumference of the insulating coating material without being twisted, and each coated wire is electrically connected to the terminal.
choke coil.
The coated wire is wound in a layered manner along the peripheral surface of the insulating coating material, and the inner peripheral surface side of the insulating coating material is composed of one coated wire on the side close to the inner peripheral surface. One layer and a second layer consisting of one covered wire are sequentially laminated on the outer periphery thereof.
The choke coil according to claim 1.
The covered wire is folded back and wound at the terminal.
The choke coil according to claim 1 or 2.
A plurality of coated wires are wound around the insulating coating material without folding back.
The choke coil according to claim 1 or 2.
The coated wire is wound around the inner peripheral surface side of the insulating coating material side so as to bulge in the center.
The choke coil according to any one of claims 1 to 4.
The terminal electrically connects the coated wire by resistance welding, welding method, or soldering.
The choke coil according to any one of claims 1 to 5.
The outer periphery of the choke coil according to any one of claims 1 to 6 is coated with a resin.
Choke coil products.